Call it automated acceptance testing, functional test driven development, checked examples or what you will—the use of automatic validation is one of the most effective tools in the Agile developer's kit.
It's a large and involved field, touching on almost every aspect of development. Handy, then, that Gojko Adzic has published a very comprehensive guide to the use of automated acceptance tests in contemporary Agile development practice, Bridging the Communication Gap: Specification by example and agile acceptance testing.
This book is a much-needed checkpoint in the on-going adventure to discover (and re-discover) how to write software effectively. Gojko is a very energetic enthusiast for these ideas, and a very experienced practitioner of them. His knowledge and expertise is present on every page.
A strong theme runs through the book—that the reason we capture examples of required behaviour and automate validation of them is to improve communication. Examples turn out to be a very powerful way to understand a problem domain and to explore a solution suitable for that domain. There turn out to be fascinating reasons for why this is true, but Gojko quite reasonably focusses on practical advice.
The main body of the book tells a story, a story of understanding, finding, and using examples to create shared understanding across a team. Gojko gives very concrete advice in a series of short chapters and explains how to do this. How to organise a workshop to find examples, how to find good examples, how to use tools to automate validation, how to use the resulting tests to guide development. Each chapter ends with a handy bullet list of key points. Together with other material on the best use for developers to make of such checked examples, and how to fit example discovery and capture into a typical Agile development process Bridging the Communication Gap provides as close to a vade mecum for newcomers to the discipline of functional test driven development as we are likely to see.
Gojko draws informative parallels with other techniques more or less strongly aligned with the Agile development world. This places the practice of Agile acceptance testing in context, and as a team-wide activity, reinforcing the cross-functional nature of the tool. Always the emphasis is on helping the various stakeholders in a development project communicate better.
There is a survey of tools available for this kind of work, which I might wish were slightly broader in scope and a little more detailed, but it does give a good overview of the market leaders. "Market leaders" in the weakest sense, since it turns out that the best tools for this kind of work are all FOSS: big-ticket corporate testing tools really aren't in this game.
Various points regarding writing and using tests are illustrated with (of course) illuminating examples. Also described are limitations of these techniques and some pitfalls to watch out for, something that more promoters of development techniques should provide.
The book is self-published and my copy was printed by Lightening Source. Books produced this way are getting better all the time, but are still not presented at the level of quality one would expect from a commercial publishing house. The pages seem very full and with the choice of font made the text a very dark colour which I don't find easy to read. The section and sub-section headings are sometimes over long and are not laid out well, a combination that I found made the book less easy to navigate than it might have been.
I will be using with book with clients and recommending it to them for future reference. A boon to the community.